EP2484230A1 - Protein-rich spirulina extracts - Google Patents

Abstract

Composition comprises an extract made of spirulina comprising at least one non blue protein and at least one phycocyanin (8-50 wt.%, based on the total protein content). INDEPENDENT CLAIM are also included for: (1) producing the composition, comprising slurrying spirulina powder in water to a suspension, stirring the suspension under a stream of air and separating the solid constituents of the suspension to obtain a crude extract; and (2) the food comprising the composition.

Description

The present invention relates to a composition comprising an extract of spirulina suitable for the preparation of foodstuffs and semi-finished food products.

There is a great interest in offering food not only in terms of taste but also visually appealing. In this context, the color of the food is an important selection criterion for the consumer. Foods that are naturally inferior in color are often mixed with dyes to make them appealing to the consumer. Furthermore, dyes can be used to compensate for the color changes or losses occurring during manufacture, processing or storage. Thus, a consistent optical quality of the product is guaranteed.

Among the dyes commonly used for food can be distinguished between synthetic and natural dyes. The most important synthetic food dyes include yellow-orange S, quinoline yellow, azorubin, allura red, tartrazine, and chochenillerot. However, these dyes are suspected to cause attention deficit hyperactivity disorder (ADHD) in children. Furthermore, these dyes can trigger allergies and allergy-like symptoms. Last but not least, the azo dyes are suspected of being carcinogenic because carcinogenic arylamine components can be released during metabolism. Against the background of these health risks, stricter food regulations, and increasing consumer health awareness, the trend is increasingly towards using natural dyes.

However, in particular with regard to the colors blue and green, this presents a special challenge. As natural blue dyes, z. As anthocyanins can be used. However, the color of anthocyanins is highly pH dependent. Thus, anthocyanins are usually at a pH in the acidic range, such as. B. in drinks, red. A blue color is reached only at a higher pH. In addition, anthocyanins are water-soluble and bleed easily when used as a food coloring. However, this disadvantage can be overcome by laking the anthocyanins. The anthocyanin is applied to a support, usually aluminum hydroxide. The aluminum coatings formed from anthocyanins have a blue color even in an acidic pH range and do not bleed. According to the declaration, such a dye is a natural dye, but relatively high levels of aluminum are present. Because aluminum is under suspicion even if such a blue dye does not meet the demands of the consumers.

To produce green dyes, either blue dyes mixed with yellow dyes or chlorophylls (E140), copper chlorophylls (E141) and the saponified chlorophyllins and copper chlorophyllins are used. However, copper chlorophylls are not naturally occurring, but are synthetically produced by reaction of magnesium chlorophyll with copper salts and, in turn, do not meet the requirements of the consumer. Natural magnesium chlorophylls and magnesium chlorophyllins are usually insufficiently stable in many acidic applications and must also be formulated in a water-soluble form with synthetic emulsifiers.

There is therefore a need for a purely natural blue or green dye.

With regard to a blue dye is the Spirulinaalge, z. B. Spirulina platensis (syn. Arthrospira platensis), of particular interest. This blue-green microalgae is known both as a dietary supplement and as a raw material for food coloring. Spirulina is rich in protein (64 to 74% by weight of dry matter), 6 to 13% by weight of lipids, of which about half are fatty acids and about 12 to 20% by weight of carbohydrates ( A. Vonshak, "Spirulina platensis (Arthrospira)", Taylor & Francis 1997, Chapter 10, pages 175 to 204 ).

$${\mathrm{C}}_{\mathrm{PC}}\left[\mathrm{mg}\mathrm{/}\mathrm{g}\right]\mathrm{=}\mathrm{F}\left\{\left(\mathrm{0}\mathrm{,}\mathrm{162}\mathrm{*}{\mathrm{E}}_{\mathrm{620}\mathrm{nm}}\mathrm{-}\mathrm{0}\mathrm{,}\mathrm{098}\mathrm{*}{\mathrm{E}}_{\mathrm{650}\mathrm{nm}}\right)\mathrm{+}\left(\mathrm{0}\mathrm{,}\mathrm{180}\mathrm{*}{\mathrm{E}}_{\mathrm{650}\mathrm{nm}}\mathrm{-}\mathrm{0}\mathrm{,}\mathrm{042}\mathrm{*}{\mathrm{E}}_{\mathrm{620}\mathrm{nm}}\right)\right\}\mathrm{/}\mathrm{EW}$$

wobei C_PC den Gesamtphycocyaningehalt angibt, C_cPC den Gehalt an c-Phycocyanin und C_APC den Gehalt an Allophycocyanin, E die Extinktion bei der gegebenen Wellenlänge ist, EW der Einwaage in g in 100 ml eines 50 mM Phosphatpuffers bei pH 6 entspricht und F ein Vielfaches einer gegebenenfalls notwendigen weiteren Verdünnung des Puffers ist ( N. Yoshikawa, A. Belay, "Single Laboratory Validation of a Method for the Determination of c-Phycocyanin and Allophycocyanin in Spirulina (Arthrospira) Supplements and Raw Materials by Spectrophotometry", J. AOAC Int. 2008, 91 (3), Seiten 524 bis 529 ).The main pigments present in spirulina are two blue water-soluble biliproteins, c-phycocyanin and allophycocyanin, which are grouped under the term phycocyanin, green chlorophylls and yellow xanthophylls. The total phycocyanin content in spirulina dry matter can be determined photometrically from two extinctions according to the following formula: $${\mathrm{C}}_{\mathrm{PC}}\mathrm{=}{\mathrm{C}}_{\mathrm{cPC}}\mathrm{+}{\mathrm{C}}_{\mathrm{APC}}$$

$${\mathrm{C}}_{\mathrm{PC}}\left[\mathrm{mg}\mathrm{/}\mathrm{G}\right]\mathrm{=}\mathrm{F}\left\{\left(\mathrm{0}\mathrm{.}\mathrm{162}\mathrm{*}{\mathrm{e}}_{\mathrm{620}\mathrm{nm}}\mathrm{-}\mathrm{0}\mathrm{.}\mathrm{098}\mathrm{*}{\mathrm{e}}_{\mathrm{650}\mathrm{nm}}\right)\mathrm{+}\left(\mathrm{0}\mathrm{.}\mathrm{180}\mathrm{*}{\mathrm{e}}_{\mathrm{650}\mathrm{nm}}\mathrm{-}\mathrm{0}\mathrm{.}\mathrm{042}\mathrm{*}{\mathrm{e}}_{\mathrm{620}\mathrm{nm}}\right)\right\}\mathrm{/}\mathrm{EW}$$

where C _PC indicates the Gesamtphycocyaningehalt, C _{CPC for} the content of c-phycocyanin and C _APC the content of allophycocyanin, E is the absorbance at the given wavelength, EW of the initial weight corresponds to g in 100 ml of a 50 mM phosphate buffer at pH 6 and F is a multiple of any necessary further dilution of the buffer ( N. Yoshikawa, A. Belay, "Single Laboratory Validation of a Method for the Determination of C-Phycocyanin and Allophycocyanin in Spirulina (Arthrospira) Supplements and Raw Materials by Spectrophotometry", J. AOAC Int. 2008, 91 (3), pages 524 to 529 ).

According to this analysis method, the Gesamtphycocyaningehalt on the Spirulina dry matter is 6 to 10 wt .-% based on the spirulina dry matter.

The total protein in foods is usually determined indirectly via the content of nitrogen by the Kjeldahl method. In this case, inorganic and organic nitrogen is converted with sulfuric acid on a CuSO ₄ / TiO ₂ catalyst to ammonia, which is distilled off and titrated for quantification. To determine the protein content, it is assumed that 16% of a protein consists of nitrogen. The nitrogen content of the sample is therefore converted by the factor 100/16 = 6.25 into a total protein content ( RE Wrolstad et al, "Handbook of Analytical Chemistry, Measurement of Protein Content - Determination of Total Nitrogen", John Wiley & Sons, 2000-2005, page 105 ; ibid. "Extraction and measurement of total lipids", page 425).

The total protein is determined by the Kjeldahl method in the spirulina algae to 60 to 70 wt .-% of the dry matter and corresponds to the literature. The remaining native non-blue proteins (nBP) present in spirulina are determined by subtraction from total protein (also referred to as Kjeldahl protein) and phycocyanin: $$\mathrm{nBP}\left[\mathrm{weight}\mathrm{,}-\%\right]=\mathrm{Total\; protein\; content}\left[\mathrm{weight}\mathrm{,}-\%\right]-\mathrm{Phycocyaningehalt}\left[\mathrm{weight}\mathrm{,}-\%\right]$$

Accordingly, 8 to 13% by weight of the total protein is phycocyanin and the remaining 87 to 92% by weight non-blue proteins in the spirulear raw materials used according to the invention.

The blue-green microalgae Spirulina platensis is used as a dietary supplement or as a raw material for food coloring. The dietary supplement is taken as a tablet or as a powder in gelatine capsules. The tablets have only a faint smell and taste of seaweed and sea. The use of the dried alga for dyeing is also possible in very dry foods, such as biscuits, crispbread or rusks. However, the use of aqueous slurries and digestions of the alga or in more moist foods, such as gummy bears, is disadvantageous because of the formation of a repulsive odor due to microbial activity, a problem which is also found in the US 2006/210545 is described. Since the blue phycocyanins already denature at 60 to 65 ° C, whereby the color is lost, aqueous slurries of spirulina algae powder can not be microbially stabilized by pasteurization.

In order to be able to dye foods with spirulina and to avoid the microbial problems, an extraction and purification of the phycocyanines is usually carried out. It will be blue-dyeing extracts which have the highest possible proportion of phycocyanins in the extracted biomass. However, much of the native non-blue protein is lost. The preparation of turquoise or green-colored extracts for coloring foods is not described.

Pure phycocyanin is used especially in Japan as a natural coloring agent for foods and cosmetics. That's how it describes JP 56-086958 extracting spirulina and treating the extract with an organic solvent to precipitate phycocyanin and convert it to a slightly water-soluble form.

Herrera et al. (J. Appl Phycol., 1989, 4, pages 325 to 331 ) describes a method in which the algal biomass is extracted with various aqueous salt solutions. When using sodium nitrate solutions, the highest content of phycocyanin is obtained; the highest purity of phycocyanin is obtained by extraction with calcium chloride. After treatment with activated carbon and ultrafiltration, 90% pure pigment is obtained.

In both described methods, however, the native, non-blue proteins are lost.

The publication WO 03/080811 describes denatured spirulina and a method of making it. The resulting denatured algae mash made of spirulina is readily soluble in water, has a pleasant taste and has a slightly blue or pink-pink color. In this document, however, an extract is obtained, which only has a very light color and thus is not suitable for dyeing food.

The publication EP 1 798 262 describes a blue paint containing natural dyes. These natural dyes can be extracted from Spirulina. However, in this reference, the natural dye is laked with an insoluble carrier. In particular, aluminum hydroxide is used as the carrier. However, due to the possible induction of Alzheimer's by aluminum, such an extract is unsuitable, in particular with regard to the consumer's health awareness.

The publication WO 03/099039 relates to a beverage that can be colored with a fluorescent agent, such as phycocyanines. The phycocyanin used is extracted from Anabaena cylindrica and spirulina. In this document, however, only pure phycocyanin is used, while the nutritionally high-quality non-blue proteins of the algae are discarded.

The publication DE 100 59 107 describes extracts of spirulina and their use in cosmetic and dermatological skin and body care products. In the described extraction process Spirulina is spray dried under mild conditions and extracted with hot distilled or mineral water or a mixture of water and a mono- or polyhydric alcohol and separated by filtration or separation. The resulting extract is subjected to ultrafiltration and stabilized with a preservative. However, the extracts described have only a yellowish brown color and are transparent. Therefore, the extracts thus obtained are not suitable for coloring foods.

The publication JP 2003-342489 relates to the recovery of an extract rich in blue phycocyanin by the addition of a basic Ca salt to an aqueous suspension of cyan-algae and separation of the precipitate.

The publication JP 2004-027041 describes to obtain a phycocyaninreichen extract with brilliant color the addition of phosphoric acid in an aqueous suspension of blue-green algae and then the precipitation of the phosphate as calcium phosphate by the addition of a calcium salt.

The publication JP 2006-230272 describes the recovery of phycocyanin with high purity. The alga is slurried in water, mixed with calcium ions and the calcium then precipitated as calcium phosphate insoluble in neutral pH and removed. The precipitation can remove unwanted impurities.

However, in these three references, the non-blue proteins are discarded.

The object of the present invention is to provide a composition which, in addition to phycocyanines, also contains native, non-blue protein material which is stable, blue to green-coloring and tasteless and odorless.

This object is achieved by a composition comprising an extract of spirulina containing at least one non-blue protein and at least one phycocyanin, characterized in that the proportion of phycocyanin is 8 to 50 wt .-%, based on the total protein content.

• Spirulinapulver in Wasser zu einer Suspension aufgeschlämmt wird,
• die Suspension unter Durchleiten von Luft gerührt wird und
• die festen Bestandteile der Suspension anschließend abgetrennt werden,

um einen Rohextrakt zu erhalten.This object is also achieved by a process for the preparation of the composition according to the invention, which is characterized in that

• Spirulina powder is slurried in water to a suspension,
• the suspension is stirred while passing air through and
• the solid components of the suspension are subsequently separated off,

to get a raw extract.

The object is likewise achieved by the use of the composition according to the invention for coloring foods and a food comprising the composition according to the invention.

Preferred embodiments are described in the subclaims 2 to 7, 9 to 11 and 13.

According to the invention, the term "non-protein protein" is understood as meaning all proteins present in addition to phycocyanin in the spirulina algae.

By "stable" is meant according to the invention that the composition according to the invention over a period of up to 12 months when stored at 4 to 10 ° C has no color change, does not gel or forms precipitates.

According to the invention, the term "odorless and tasteless" means that the composition according to the invention does not alter the odor and taste of the food which it is used to produce.

The term "extract" according to the invention a product understood that by extraction with a solvent such. As water or aqueous solutions of alcohol, in a manner known in the art, for. As maceration or percolation is obtained.

• Spirulina platensis
• Spirulina fusiformis
• Spirulina maxima.

The extract is extracted from spirulina, a genus of cyanobacteria. These include:

• Spirulina platensis
• Spirulina fusiformis
• Spirulina maxima.

In a preferred embodiment in connection with one of the embodiments mentioned above or below, the extract is obtained from Spirulina platensis .

The extract is prepared from spirulina powder extraction methods known to those skilled in the art. Spirulin powder is obtained by drying and crushing the spirulina algae.

In a preferred embodiment in conjunction with one of the embodiments mentioned above or below, the phycocyanine content is 8% by weight to 10% by weight, based on the total protein content, and has a green color. In a blue or turquoise extract concentrate the Phycocyaningehalt is 10 wt .-% to 50 wt .-%, based on the total protein content, more preferably 16 wt .-% to 40 wt .-%, in particular 20 wt .-% to 30 wt. -%.

In a further preferred embodiment in conjunction with one of the embodiments mentioned above or below, the weight ratio of non-blue protein to phycocyanin is 1: 1 1 to 10: 1, more preferably 2: 1 to 7: 1, in particular 3: 1 to 5: 1 ,

Furthermore, in a preferred embodiment, the composition according to the invention in combination with one of the embodiments mentioned above or below contains from 0.5 to 2% by weight, particularly preferably from 0.8 to 1.2% by weight, of phycocyanin, based on the total composition.

In a further preferred embodiment in conjunction with one of the embodiments mentioned above or below, the total protein content of the composition is from 2 to 20% by weight, particularly preferably from 5 to 15% by weight, in particular from 8 to 10% by weight, based on the total composition.

Furthermore, in a preferred embodiment, the composition according to the invention may contain at least one chlorophyll in conjunction with one of the embodiments mentioned above or below. The composition particularly preferably contains chlorophyll a. Preferably, the chlorophyll contained in the composition is also derived from spirulina.

The composition according to the invention contains in a preferred embodiment, in conjunction with one of the embodiments mentioned above or below, from 0.01 to 0.3% by weight of chlorophyll, based on the total composition. The chlorophyll content is particularly preferably 0.05 to 0.25% by weight, based on the total composition, in particular 0.1 to 0.2% by weight. Preferably, the chlorophyll content for green extracts 0.1 to 0.2 wt .-%, based on the total composition. Turquoise extract concentrates preferably contain 0.01 to 0.02 wt .-% chlorophyll, based on the total composition, in particular 0.015 wt .-%.

Blue extracts contain no measurable amounts of chlorophyll without additional enrichment steps. The chlorophyll content in a blue extract according to the invention is less than 0.002% by weight, based on the total composition.

• 0,1 g Algenpulver oder 2 ml Extraktkonzentrat werden in 4 ml Wasser suspendiert, mit 96%igem Ethanol auf 100 ml aufgefüllt und 60 min unter Rühren bei Raumtemperatur extrahiert. Der Extrakt wird über einen Faltenfilter gegeben und 2 ml Filtrat werden in eine 1 cm Küvette überführt. In einem Photometer wird die Extinktion (E_660nm) bei 660 nm gegen 96%iges Ethanol bestimmt. Der Chlorophyllgehalt C_Chloro in g/kg errechnet sich aus der Extinktion bei 660 nm (E_660nm) gegen 96%iges Ethanol, der Einwaage EW in g und, sollte die Extinktion nicht <1 sein, einer notwendigen Verdünnung des Filtrats um F nach: $${\mathrm{C}}_{\mathrm{Chloro}}\left[\mathrm{g}\mathrm{/}\mathrm{kg}\right]\mathrm{=}{\mathrm{E}}_{\mathrm{660}\mathrm{nm}}\mathrm{x\; F}\mathrm{/}\mathrm{EW}\left[\mathrm{g}\right]\mathrm{/}\mathrm{577}$$
  

The chlorophyll content is determined as follows:

• 0.1 g of algae powder or 2 ml of extract concentrate are suspended in 4 ml of water, made up to 100 ml with 96% ethanol and extracted with stirring at room temperature for 60 min. The extract is passed through a pleated filter and 2 ml of filtrate are transferred to a 1 cm cuvette. In a photometer, the absorbance (E _{660 nm)} at 660 nm against 96% ethanol is determined. The chlorophyll content C _Chloro in g / kg calculated from the absorbance at 660 nm (E _{660 nm)} to 96% ethanol, the initial weight EW in g and, the absorbance should not be <1, a necessary dilution of the filtrate to F by: $${\mathrm{C}}_{\mathrm{chloro}}\left[\mathrm{G}\mathrm{/}\mathrm{kg}\right]\mathrm{=}{\mathrm{e}}_{\mathrm{660}\mathrm{nm}}\mathrm{x\; F}\mathrm{/}\mathrm{EW}\left[\mathrm{G}\right]\mathrm{/}\mathrm{577}$$
  

Furthermore, in a preferred embodiment, the composition according to the invention in combination with one of the embodiments mentioned above or below as further additives acidulants, such as citric acid or tri-sodium citrate, flavorings, flavorings, preservatives, such as potassium sorbate, fruit and plant extracts and their concentrates, z. From Carthamus tinctorius petals, Gardenia jasmine berries, safflower blossom leaves or gardenia yellow, sweeteners, antioxidants such as ascorbic acid, carotenoids, as well as combinations of two or more additives.

In a preferred embodiment, the composition according to the invention in combination with one of the embodiments mentioned above and below has 50 to 75 ° Bx, particularly preferably 65 to 70 ° Bx. The green extract preferably has 50 ° Bx.

In the process according to the invention, spirulina powder is slurried in water to a suspension, the suspension is stirred while passing air through it, and then the solid constituents of the suspension are separated off. In a preferred embodiment in conjunction with one of the embodiments mentioned above or below, the weight ratio of spirulina to water is 1:20 to 1:40, more preferably 1:30. Preferably, the suspension is macerated for 3 to 36 hours at 5 to 30 ° C, more preferably for 5 to 18 hours at 5 to 20 ° C. The slurry is preferably carried out with a rotor-stator dispersion unit.

By this procedure, the typical unpleasant odor development is prevented.

Furthermore, in the method according to the invention in a preferred embodiment in conjunction with one of the embodiments mentioned above or below, the solid constituents are separated in a centrifuge, via layer filters and / or microfiltration.

In a preferred embodiment in conjunction with one of the embodiments mentioned above or below, the crude extract obtained is filtered for further purification, treated with a stabilizer and evaporated in an evaporator at a temperature of 50 to 70 ° C at 10 to 100 mbar to a concentrate. The vapors are then rejected. The stabilizer used is preferably sucrose and invert sugar. The concentrate can then be treated with a carrier material, such as maltodextrin, and spray-dried.

The green extract is preferably only centrifuged and concentrated in the method according to the invention.

In a preferred embodiment in conjunction with one of the embodiments mentioned above or below, a commercial layer filter is used for filtration of the crude extract, such as. B. a layer filter of the K series by Pall Seitz Schenk, D-74564 Crailsheim. Preferably, a clarification filtration and / or a sterile filtration is performed. The pore size of the layer filter is preferably 2 to 7 microns for the Klärfiltration and less than 0.8 microns for sterile filtration.

The composition according to the invention is used for the production of foods. Preferably, the composition of the invention for the production of colored drinks, dairy products, ice cream, confectionery or coatings for drageeing, such. As chocolate cores, nuts, chewing gum and sugar pearls used.

Preferably, the food contains 0.1 to 2 wt .-%, particularly preferably 0.2 to 1.5 wt .-% of the inventive composition, based on the food.

Surprisingly, the composition according to the invention contains a high content of native, non-blue protein material from Spirulina. Furthermore, the composition has no precipitation and does not gel and is water-soluble without the addition of emulsifiers.

When coloring foods, in particular foods with a residual moisture content of at least 20 wt .-%, based on the food, with the composition according to the invention There is no bad smell or taste, and the color is stable for 1 year at 20 ° C.

The present invention will be further illustrated by the following examples.

EXAMPLES Example 1: Preparation of Spirulina Green Extract

18.5 g of spirulina algae powder (17.7 g algae dry mass, 0.8 g residual moisture) are slurried in 555 g of cold water in a coolable jacketed vessel, stirred for 1 min at 7600 revolutions per minute (IKA Ultraturrax T50, Mittelfein) and with careful passing of Air (aquarium pump Elite 802, Hagen Germany, 25488 Holm) for 4 h at 15 ° C continuously stirred. Thereafter, it was macerated at 5 ° C for 16 h without stirring with continuous passage of air. The solid components are separated in a centrifuge, the resulting thin extract is mixed with 38.2 g of sucrose and evaporated to 100 g of concentrate at 50 ° Bx.

The extract concentrate contains 0.92% by weight of phycocyanin, the total protein content is 9.6% by weight. The weight ratio of non-blue protein (9.6 wt% -0.92 wt% = 8.68 wt%) to phycocyanin (0.92 wt%) is 8.68 / 0.92 = 9.45: 1, the proportion of phycocyanin in the total protein thus 0.92 / 9.6 = 9.6 wt .-%. Further, chlorophyll contained in the algae powder is extracted and remains in the extract concentrate. The chlorophyll content is 0.15 wt .-%, based on the total extract. In combination with the blue phycocyanin, this results in a green extract.

Example 2 Preparation of Spirulina Turquoise Extract

40 g of spirulina algae powder (38.24 g of dry algae, 1.76 g of residual moisture) are slurried in 1.27 l of cold water and stirred briefly. Carefully passing air is macerated for 16 h at 10 ° C. The solid components are separated in a centrifuge and obtained a thin extract. This is filtered through layer filters from Pall Seitz Schenk K100 and KS50. Subsequently, the extract is mixed with 58 g inverted sugar syrup with 78 ° Bx and evaporated to 100 g concentrate at 70 ° Bx.

The Phycocyaningehalt in the extract concentrate is 1.7 wt .-%, the total protein content 7.7 wt .-%. The weight ratio of non-blue protein (7.7% by weight - 1.7% by weight = 6% by weight) to phycocyanin is 6: 1.7 = 3.5: 1, ie the proportion of the phycocyanin in the total protein 1.7 / 7.7 = 22% by weight. The chlorophyll content in the extract concentrate is 0.015 wt .-%, based on the whole extract. In combination with the phycocyanin results in a turquoise color of the extract.

Example 3: Preparation of Spirulina Blue Extract

The turquoise thin extract prepared according to Example 2 is filtered through Seitz layer filter EKS. Subsequently, the extract is mixed with 58 g of invert sugar syrup with 78 ° Bx and evaporated to 100 g of concentrate at 70 ° Bx.

The additional, particularly fine degerming filtration removes the last residues of chlorophyll.

The Phycocyaningehalt in the extract concentrate is 1.9 wt .-%, the total protein content 9.3 wt .-%. The weight ratio of non-blue protein (9.3 wt .-% - 1.9 wt .-% = 7.4 wt .-%) to phycocyanin is 7.4: 1.9 = 3.9: 1, the proportion of Phycocyanins in the total protein so 1.9 / 9.3 = 20.4 wt .-%.

In each case, 10 g of the green, turquoise and blue extracts obtained according to Examples 1 to 3 were added to 1 kg of gelatin mass. After 6 months at 20 ° C no change in taste or smell is observed.

Claims (14)

A composition comprising an extract of spirulina containing at least one non-blue protein and at least one phycocyanin, characterized in that the phycocyanine content is 8 to 50% by weight, based on the total protein content. A composition according to claim 1, characterized in that the Phycocyaningehalt is 16 to 40 wt .-%, based on the total protein content. A composition according to any one of claims 1 or 2, characterized in that the phycocyanine content is 0.5 to 2 wt .-%, based on the total composition. Composition according to at least one of Claims 1 to 3, characterized in that the total protein content of the composition is from 2 to 20% by weight, relative to the total composition. Composition according to at least one of Claims 1 to 4, characterized in that it also contains at least one chlorophyll. Composition according to Claim 5, characterized in that it contains from 0.05 to 0.3% by weight, relative to the total composition, of chlorophyll. Composition according to at least one of Claims 1 to 6, characterized in that it also contains carotenoids, safflower blossom extract, gardenia yellow extract or mixtures thereof Process for preparing a composition according to at least one of Claims 1 to 7, characterized in that - spirulina powder is slurried in water to a suspension, - The suspension is stirred while passing air and the solid constituents of the suspension are subsequently separated off, to get a raw extract. A method according to claim 8, characterized in that the spirulina powder is mixed with water in a weight ratio of 1:20 to 1:40. A method according to any one of claims 8 or 9, characterized in that the suspension is stirred for 3 to 36 h at 5 to 30 ° C while passing air. A method according to any one of claims 8 to 10, characterized in that the crude extract is filtered for further purification, is mixed with a stabilizer and is evaporated in an evaporator at 50 to 70 ° C and 10 to 100 mbar to a concentrate. Use of the composition according to at least one of claims 1 to 7 for coloring foods. Use according to claim 12, characterized in that the food is a drink, a milk product, ice cream, confectionery or a coating for drageeing. Food comprising the composition according to any one of claims 1 to 7.